1. Field of the Invention
The present invention relates to a cassette accommodation case suited for accommodating a tape cassette such as, for example, an audio compact cassette and the like and particularly, to a cassette accommodation case of a slide type for accommodating a tape cassette by laterally inserting the tape cassette from an inserting mouth portion provided on one side thereof.
2. Description of the Related Art
In recent years, in a cassette accommodation case for accommodating and keeping an audio compact cassette, a cassette accommodating case of a slide type for laterally inserting a cassette from an inserting mouth portion provided on one side thereof has been practiced.
The structure of the conventional cassette accommodation case of side type will be shown in FIG. 1 to FIG. 5.
In FIGS. 1 to 5, reference numeral 1 indicates a cassette accommodation case 1 and an audio compact cassette (hereafter, referred to simply as a cassette) 10 is accommodated in the cassette accommodation case 1 by being laterally inserted from an inserting mouth portion 2 provided on the one side thereof of the cassette accommodation case 1.
First of all, the structure of the cassette 10 will be explained. As shown in FIG. 1, there are formed hub driving shaft inserting holes 12 on the left and right of a cassette housing 11 of the cassette 10 and corresponding to the hub driving shaft inserting holes 12, a pair of hubs 14 for winding a magnetic tape 13 are rotatably accommodated inside the cassette housing 11.
On the front surface of the cassette housing 11 is formed an opening portion 15 through which the magnetic tape 13 is exposed, while inside the cassette housing 11, a tape transit path is formed in a way that the magnetic tape 13 led out from the hub (supplying side hub) 14 on one side is wound around the hub (takeup side hub) 14 on another side through the opening portion 15.
A magnetic head and the like are to be inserted in the opening portion 15 from a cassette deck side. In order to secure the thickness at a portion into which the magnetic head and the like are to be inserted, trapezoid shaped swelled portions 16 which swell to the upper and lower sides of both surfaces are formed at the front portion of the cassette housing 11.
The cassette accommodation case 1 into which the cassette 10 is inserted is structured by uniting an upper half 1A and a lower half 1B. The upper half 1A is a molded plastic product molded from, for example, GPPS (general purpose polystyrene) as its material and also, the lower half 1B is a molded plastic product molded from, for example, HIPS (impact-proof polystyrene) as its material. The upper half 1A and the lower half 1B are integrally united by means of ultrasonic-welding and the like while in a state of being united.
Then, the inserting mouth portion 2 is provided on one side surface side of the cassette accommodation case 1 with its surface being wholly opened, and the cassette 10 is laterally inserted into the cassette accommodation case 1 from the inserting mouth portion 2 in a sliding fashion.
The cassette accommodation case 1 is such that the cassette 10 is accommodated therein almost without any clearance. To this end, on the respective inner surfaces of the upper half 1A and the lower half 1B inside the cassette accommodation case 1, concave grooves 3a and 3b for escaping the swelled portions 16 of the cassette 10 are respectively formed in a lateral direction, that is, in a cassette inserting direction.
Also, nearly at a central portion of the upper half 1A of the cassette accommodation case 1, a long opening portion 4 of an oblong shape in the cassette inserting direction is formed. When the cassette 10 is to be taken out from the cassette accommodation case 1, the cassette 10 is pushed out by putting a finger (for example, a thumb) from the opening portion 4.
Further, a stopper tab 5 is provided inside the cassette accommodation case 1 so as to prevent the cassette 10 from unexpectedly jumping out from a state of the cassette 10 being accommodated in the cassette accommodation case 1.
The stopper tab 5 is integrally projectingly formed on the lower half 1B and an engaging convex portion 5a is provided at a tip end portion thereof. Then, in the state of the cassette 10 being accommodated in the cassette accommodation case 1, the engaging convex portion 5a of the stopper tab 5 is, as shown in FIG. 5, engaged with an edge of an aperture portion 18 in which an erroneous erasure protection detecting nail 17 for the cassette 10 is provided, which keeps the cassette 10 in a lightly locked state in the cassette accommodation case 1, thereby preventing the cassette 10 from unexpectedly jumping out (coming off) from the cassette accommodation case 1.
Further, a rotation stopping member 6 is equipped inside the cassette accommodation case 1 for preventing the magnet tape from becoming loose by blocking the unnecessary rotation of the hubs 14 in the cassette 10.
The rotation stopping member 6 is a molded plastic product molded from, for example, PP (polypropylene) as its material and is structured in a way that rotation stopping projecting tabs 8 corresponding to the hub driving shaft inserting holes 12 of the cassette 10 are projectingly formed on a base plate portion 7 to be capable of elastically rising and falling, and the base plate portion 7 is attached by being caulked and fixed to caulking projections 9 projectingly provided nearly at a central portion inside the lower half 1B.
Then, when the cassette 10 is inserted into the cassette accommodation case 1, the rotation stopping projecting tabs 8 are pushed down by the cassette 10. Further, when the cassette 10 is completely accommodated in the cassette accommodation case 1, since the hub driving shaft inserting holes 12 of the cassette 10 correspond to the rotation stopping projecting tabs 8, respectively, the rotation stopping projecting tabs 8 elastically each revert to an erect state and engage with engagement projecting tabs 14a on an internal circumference of the hubs 14 to block the rotation of the hubs 14.
With the above-mentioned conventional cassette accommodation case 1, because the rotation stopping projecting tabs 8 become a state of being pushed down every time the cassette 10 is pushed therein and pulled out therefrom, a so-called state of deformation due to fatigue occurs in the rotation stopping projecting tabs 8, and in that case, the rotation stopping projecting tabs 8 do not almost revert to a state of erection when the cassette 10 is completely accommodated and become a state of not engaging with the hubs 14, with the result that it becomes impossible to prevent the hubs 14 from unnecessarily rotating.
Also, in a case where the rotation stopping projecting tabs 8 erect incompletely, depending on circumstances, the tip ends of the rotation stopping projecting tabs 8 get stuck in a clearance between the hubs 14 and the hub driving shaft inserting holes 12 and get bent and folded, and as a result, in this case too, there is the loss of the function in preventing the hubs 14 from unnecessarily rotating.